Fuse.



L. w. oowmEs & R. C. PATTON.

FUSE.

APPLI'CATION FILED oc'r.12,191s.

PatefitedJune 25, 1918.

"M M a 0L0 MW 0 AF W W am UNITED STATES Pfifi ifrili iilf LOUZIS 'W.DOWNES AND EALPH CLIFTON PATTQIQ, 313' PREFVIDEWQE, RHGDE ISLAND,

ASEIGNORS TO D 8: W. FUSE CGMPANY, OF ERGVIDEKQJE, RHQZUE PQBATIDN 01FRHUIDE ISLAND.

mien.

Anylication filed @etc'nez 12, 1918.

To all wkom izfmayconcem Be it known that We, LOUIS VI. DOWNES and RALPHCLIFTON PATTQN, citizens of iihe United States, and residents of thecity of 5 Providence, vin ithe ccunty of Providence and State of RhodeIsland, have invents certain new and. useful lmpi'cvenicn'ts in Fuses,which the follewing is a specifics.-

extinguish the the auxiliary ink finally A 'fiurthei' cbjeci: 07f enticni 1 provide an electric fuse Wing fusible link i. cylindrical shape an ito .c'vicle en air chamber for said link ifcnncu both on fihe inside andon the outside 0% 'fhe cyli nler for a portion of its length.

It is found in practice ihzu'; when the mm rent slowly creeps up beyondthe maximum carrying capacity 0f the fuse; the link begins to oxidize onits surface, and if mein- .aineci at a ci'i ical temper? 'ure just belowhis mel'b ng r l l coating 0- cxid cf en iJcf/Oi l I support the meta}Within it even when has become melied and when a sf suppressing materielies gig-"e I conic-(l link '1: serves support L n n and prevent sherupture W1 i-wlse occur.

order to obviate this serious diliiculcy eventing the rupture of shelink 1* time, we nave prev; e he in ale and nits link Y nch sn 7' are pi i M'- eu. to egisiei one wiiih the other so film's h the inside andoutside wells of the link soacc c ciy un uppoiteih I ei ht of then'ieqni will he slain of of because slain has nci ;h in itself to 4metal.

encther eds -e cf the space enera'lly einplo gcei e securc=- bySpecificaticn of ile'tiiers Eat n-L Serial high temperatinesv This hasbeen termed the Nei'nst eiifect, an example of Whichmay be seen in thewell-known 'hernst lamp.

The air chambers divide the filling mate- Iilll end so prevent h ghlyheated layers of the same from serving as a conductor to reestablish thecircuit after the link is blown. The desirnbie effects secured by theair chambers aid in the quiet operation of any fuse, QIBiJaltlCllllflYvaluable when used in a main fuse connected electrically in peravllclwith an auxiliary fuse.

Vfih these and other objects in View, the invention co. cf certain novelfeatures 01 "l he more fully de- W i iznzly pointed cue in the crewing'sctiional side elevation of a n LUSH: showing; an auxiliary fuse mount-2- 1s a side eievnticn partly in section fuse with s :ubnl n1 fuse linkhavch inber formed about it.

- an 83141 View of the construe e sectional. end View on line 2 throughone row of metal reticnnl side elevation of a in link belng providedecznnoun f icle.

n beinn' which heads are in 1e contact plates 12 exeui; through the endcaps 13 of the a 'zn'rn supported on miin inner chamber 16 is formed byproa pair disks 20 and 21 which are i Spllfifill upzirt relation by oneor more If s 22, ouch of which pins is shouldered us :it 23, the reducedportion extending irough openings in the mic-u disks.

The Walls of the inner chumber are preferably arranged in line withthose of the outer chuzuluu' so tluit the air chambers on both. sides ofthe link will register.

n order to somewhat Weaken that portion of the Wull of the tubular link,which lies Within the air chamber, We hure formed u. plurality of srnullholes 2 1': through the body of the linl; udiecent one of the chzuuberWilllS and a similar row of holes 25 adjacent the opposite Well of thechamber,thereby weulrening the linlr between these holes so as to insure1ts rupturing within the chamber.

A filling of are suppressing materiel is pressed both into the ii sideof the tubular link and also about the outside of the some, completelyfilling the casing except the sec: tions between the wells of the innerand outer chan'ibcrs.

By this construction, it will be observed that the walls of the tubularlinlt are entirely uusugported within the chambers, whereby when fused,the metal will drop 21nd disperse breaking the eircuit at this point.

lt is found in practice that the use of an.

air chamber in a. compound. fuse greatly increases the efiiciency ofsuch a fuse particularly in hi h current and high voltage circuits. l r"drawings illustrates cartridge form of compound fuse in which or moreauxiliary fuses 2G greater electrical resistance are connectedelcctricelly in parallel with the main fuse.

lit has been found in large compound fuses, particularly those having uvoltage of sin hundred or more, that when an air space is not employedulirout the main link, the are sometimes reestziblishes itse f in themain fuse, the auxiliary link is runtured. T his has been found to bedue to the feet that either the skin of metallic oxld has not beenentirely broken, or else the illing of are suppressing mute-rial aboutthe main link has become a conductor due to its high temperature W henthe air chtunber is employed in e. compound fuse, the main link ruptureswith in the chamber upon the passage of un ere cessive current Withoutthe fornwtiou of u. violent ere because i this main linl; melts thepeter tl ucrcss the gap forlned'in it very l ue to the fact that themain link nected in nerullel with shunt circuit in the form un auxthesmell i iliury link. he formed at the breei n entirely tingulshed linkopens the circuit. It is then impossible for the circuit to reestablishitself through the main fuse.

in some insluuces instead of mounting the auxiliary fuse in u SCPLlilliQcasing and on the oulside of the main casing, es illustrated in Figs. 1,'2 and S, We construct the auxiliary element in a coil or helicul form.L? and mount it in the some casing with the main fuse 10 as illustratedinFig". 5 but any cooperating arrangement of main and ens:- iliery fuselinks adopted to operate in connection with en ,uir chamber is intendedto full Within the scope of this invention.

Our present invention lies first, in the provision. of u compound fusehaving fuse links ofeuy shape and providing an air chamber about themain fuse link for too purpose above described; second, to provide atfuse having a tubular fuse link With en air charm leer, both on theoutside and on the inside of the link; and third, the provision of acompound fuse having a main link in tubu- .ler form, said main linkhaving an air chumber both on its inside and on its outside, said ineinfuse link being arranged to Work in conjunction with an auxiliary fuselinl; of any shape or form and connected with it in. parallel.

Having thus described one illustrative; mnbodinient of our invention, Wedesire it to be understood that the details of construction may bevaried Without departing from the spirit of the invention, the scopewhich is defined by the appended claims We claim:

El. in en electric fuse, the couiloineticui. a main fuse link and anauxiliary fuse liulr connected together electrically in parallel, on airchamber formed about said niuin limit for :1 portion of its length, saidauxiliury fuse being of a capacity sufficient to prevent the drawing outof on are Within the air chamber upon the melting of the muin fuse linkbefore the auxiliary link finally opens the circuit.

Q. In an electric fuse, a cylindrical fuse link, a filling of aresuppressing material about said linlr and an stir chamber formed bothinside and outside of said cylinder for, a portion of the length of thefuse.

3. ln an electric fuse, e cylindrical fuse link, a filling of aresuppressing material in said fuse, and an air drum formed both on ti eoutside and on the inside of said cylinder d drums registering with eachother.

4. ln en clec tric if use, a cylindrical fuse linlr, an air drumformedon theoutside of said link, en air drum formed on the inside ofseid linlr, said drums registeri with each b other, and a filling of aresuppressing; mate. rral about sand, drums.

5. ln an clectri fuse, a casing, cylin .ri-

ce l fuse linlr mounted in send casing, an e lie llllli chamber formedon the inside and about the outside of said link, the walls of said linkbeing weakened between said chambers.

6. In an electric fuse, an outer casing, a cylindrical fuse link mountedin said casing, air drums having two side walls formed both on theoutside and on. the inside of said cylinder, spacers for separating andsupporting said Walls, and a filling of arc suppressing material paekedagainst both of said walls.

7. In an electric fuse, a casing, a cylindrical fuse link in saidcasing, a filling of are sup ressing material about said link, an airchamber formed on both the inside and outtures in presence of twowitnesses LOUIS W. DOWNES. RALPH CLIFTON PATTON. Witnesses:

, GEORGE W. STEERE,

P. O. BAKER.

